Hi, do you mean in the "Shortcuts" section of the built-in Firefox Home / new tab page?

There isn't a setting less than 1 row (or any units other than rows). There might be a way to plug in a blank page for ones you want to be blank so Firefox doesn't fill them, but it would be easier to put in actual pages.

Maybe another support volunteer will have a better suggestion.

If you searched on the firefox forum there was something related to this. how can i limit the number of websites shown on the new tab page? https://support.mozilla.org/en-US/questions/988065

That was for an older design of the page from a few years back...

You can possibly pin websites to tiles you do not want Firefox to fill from the history.

See also:

• https://support.mozilla.org/en-US/kb/customize-new-tab-page
• https://support.mozilla.org/en-US/kb/hide-or-display-content-new-tab